One of the first applications of solid expandable tubular technology, which promises a revolution in drilling and well engineering, has been carried out by Petroleum Development Oman (PDO) in one of its wells at Qarn Alam, in central Oman.

Expandable tubing technology is what the name says: steel tubing of a certain diameter is literally made wider by drawing a cone of a larger diameter through it. The application at Qarn Alam is the first time this cutting-edge technology has been used in the Middle East. In fact, the technology has so far been applied only a few times in the world.

The technology was developed by Shell Technology EP in the late 1990s and progressed by two joint-venture companies, e2TECH (Shell and Baker Hughes) and Enventure (Shell and Halliburton). The metallurgy derives from the steels developed for the automobile industry.

The project at Qarn Alam involved using the tubing as a patch to shut off a set of perforations in a well.

A section of the novel tubing was used at a depth between 1167 and 1190 metres. In addition, a second length of pipe was set at a depth between 1692 and 1720 metres to increase fluid velocity.

The project itself, while only modest in its ambitions, marks the first step of a revolution in well engineering.

Wells are drilled and lined with casing one section at a time. A new section of a well can therefore only be constructed if the drill bit and subsequent casing have a diameter smaller than the previous section. Hence, all conventional wells are forced to have a characteristic 'telescope' profile. Expandable tubing, when used as casing, promises to change that.

"What we achieved in Qarn Alam will have huge implications for the way forward in PDO," says PDO's Senior Well Engineer, Paul Francis. "This technology will ultimately translate into improving our capacity to increase production. We can't overstate what this technology will mean."

The technology heralds the possibility of access to deeper reservoirs, which could be of particular benefit in Oman, where oil reservoirs can be several thousands of metres below the surface. PDO's newest field, Al Noor, brought on stream last month, is one such area.

The success of the expandables is being seen as overcoming the first hurdle to achieving the dream of drilling, a mono-diameter well - a well with the same diameter casing from top to bottom.

Joe Straccia, PDO's Technology Manager, said: "Expandable tubular technology truly has the potential to 'change the game' and represents a major advancement that the exploration and production industry has long awaited.

PDO is committed to getting this technology into the ground and being a leader in many aspects of its implementation."